Which muscle is NOT considered a glottal adductor?

The cricothyroid muscle is not considered a glottal adductor because its primary function is to tense the vocal folds by tilting the thyroid cartilage forward relative to the cricoid cartilage. This action elongates the vocal folds and increases pitch, but it does not contribute to the adduction of the vocal folds, which is crucial for closing the glottis during phonation.

In contrast, the transverse interarytenoid and oblique interarytenoid muscles play significant roles as glottal adductors. The transverse interarytenoid muscle pulls the arytenoid cartilages together, effectively closing the glottis. Similarly, the oblique interarytenoid muscle aids in adducting the vocal folds by drawing the arytenoids closer together in a crisscross pattern.

The lateral cricoarytenoid muscle also functions as a glottal adductor by rotating the arytenoids medially, helping to close the glottis for phonation. Thus, the primary distinction of the cricothyroid muscle lies in its function of adjusting pitch rather than facilitating closure of the vocal folds.